And no--I'm not saying the Maison is cheating. I'm saying that they only need one win, while you need 50.
But if all that separates a win from a loss past, say, battle 30 is a 95% move missing once, and you're using one twice a battle from 31-50, you WILL lose by 50 87.1% of the time--FAR more often than you win all 50. And that's ignoring crits. So the fact is that all luck can do for you is win you one battle, whereas for the AI, it can end the streak.
Ding ding ding! The game isn't cheating in the sense of tweaking the RNG, but there's nothing at stake for an AI loss, A player loss resets your progress, so the player can't really afford to rely on 30% OHKO odds or even higher but imperfect accuracy moves. The streak based scoring to get a couple of junk berries is the actual worst.